S. 54 : Capital gains-Profit on sale of property used for residence-Investment in under construction residential house-Expiry of three years from date of sale of original asset-Investment in under construction flat-Utilised only half amount of long term capital gains-Balance amount of long-term capital gain should be charged to tax under section 45 in year under consideration, being year in which period of three years from date of transfer of original asset expired.[S. 45, 54(2)]